Apparatus and method for waking up a  processor

ABSTRACT

An apparatus and method for waking up a main processor (MP) in a low power or ultra-low power device preferably includes the MP, and a sub-processor (SP) that utilizes less power than the MP to monitor ambient conditions than the MP, and may be internalized in the MP. The MP and SP can remain in a sleep mode while an interrupt sensor monitors for changes in the ambient environment. A sensor is preferably an interrupt-type sensor, as opposed to polling-type sensors conventionally used to detect ambient changes. The MP and SP may remain in sleep mode, as a low-power or an ultra-low power interrupt sensor operates with the SP being in sleep mode, and awakens the SP via an interrupt indicating a detected change. The SP then wakes the MP after comparing data from the interrupt sensor with values in storage or with another sensor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 13/595,119 filed on Aug. 27, 2012 and entitled andclaims the benefit of an earlier Korean Patent application filed inKorean Intellectual Property Office on Jul. 26, 2013 and assigned SerialNo. 10-2013-0088382, the entire disclosure of which is herebyincorporated by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a low-power wake-up method for anelectronic device having a sensor. More particularly, the presentinvention relates to ways to reduce battery power utilized by portabledevices and facilitate a return of the electronic device to operationfrom a sleep mode.

2. Description of the Related Art

In order to save power, which is of particular importance to batterypowered devices, conventionally a “sleep mode” has been utilized,typically when the electronic device is an idle state for apredetermined amount of time.

Battery usage in portable electronic devices, including but not limitedto cell phones, smart phones, tablets, personal digital assistants(PDA's), portable music players, etc., are just a few of the many typesof devices where battery usage is critical, and there continues to be aneed to provide more functionality and at the same time reduce powerbattery usage.

Conventional devices, wherein after a period of time of non-usage, maydim the brightness of the display, or the display goes blank to conserveenergy.

For example, with regard to computers, sleep mode is defined as anenergy-saving standby condition of a computer which can be reactivatedby external stimulus, such as touching the keyboard. For example, when anotebook computer goes into sleep mode, the display screen and diskdrive are normally shut down. Once awakened (i.e. sent a specificsignal), the computer returns to its former operating status.

Moreover, in the case of portable electronic devices, sleep modeoperates, for example, in devices that are in no way limited tosmartphones, tablets, music players, Personal Digital Assistant (PDAs),just to name a few possibilities.

In fact, many smartphones now default to a sleep mode when not used,unless actively performing certain tasks. When there are no active userinteractions such as screen touches, every component, including thecentral processor, can stays off unless an app instructs the operatingsystem to keep the device fully powered on.

Moreover, a number of background operations need to be performed whilethe phone is idle. In one such example, a mailer may need toautomatically update email by checking with a remote server. To preventthe phone from going to sleep during such operations, smartphonemanufacturers often make application programming interfaces, or APIs,available to app developers. The developers insert the APIs into apps toinstruct the phone to stay awake long enough to perform necessaryoperations.

In a typical smartphone, an Application Processor (AP) is asleep whenthe device is asleep. In order to wake up the device, conventionalsystems require the user to press a power button or an unlock button.

Sleep mode saves battery power, particularly when compared with leavinga device in fully operation state while idle, and advantageously permitsthe user to avoid having to reset programming codes or wait for anelectronic device to reboot. In wireless electronic devices, such asportable mobile terminals, tablets, etc., which often seek out networksand have to provide passwords to obtain access upon being rebooted orreset, the use of sleep mode is preferable to a rather cumbersome andslow process or rebooting.

However, to return to an operational mode from a sleep mode (wake mode)requires an action to be undertaken by the user. For example, a powerbutton or an unlock icon must be pressed, which is slow and sometimesawkward, especially when trying to quickly perform an action on theelectronic device. Even in the case of a virtual keypad, an unlock iconmust be touched or spread in order to restore the electronic device toan operational mode, meaning that the user is inconvenienced bycontacting a button of the device, or sliding their finger along ascreen.

Some conventional attempts to solve some of the shortcomings includeproviding a luminance sensor or a camera. However, in such cases theapplication processor (AP) cannot go into sleep mode and must always bein an operating mode to process sensed data from the sensor or camera.This type of monitoring requires a high amount of power consumption, asit is impossible to control the sensor by the AP directly when the AP isasleep.

Recently, the use of a lower power processor for processing only thesensing data has been configured into the devices. However, the lowpower processor processes data from the sensor using a polling type, andmust be maintained in a wake-up state, using significant amounts ofpower.

With regard to conventional attempts to address the above-discussedissues, U.S. Pat. Appln. Pub. No. 20100313050 discloses that a sensorprocessor system selects a power profile to be applied to theapplication processor system based on the sensed data, and instructs thepower management controller to apply the selected power profile to theapplication processor system. There are two processors used for lowpower sensing that wakes up the AP when the sensed data meets thecondition.

However, a significant drawback to U.S. Pat. Appln. Pub. No.2010/0313050 is that the sensor processor always operates to monitorambient environment using a polling type sensor without a sleep mode.The sensor processor applies the power profile to the applicationprocessor system (S/W type).

In another conventional attempt to improve the art, in U.S. Pat, Appln.Pub. No. 2009/0259865, the electronic device includes a circuitconfigured to operate when the main processor is in the sleep mode. Thecircuit comprises at least one low power processor and a sensor.However, the low power processor in the conventional system alwaysoperates without being in sleep mode in order to be able to monitorambient environment via a polling-type sensor.

Accordingly, there is a need in the art for a system and method thatpermits additional components to be in sleep mode and yet, providesambient monitoring of the device, and can permit a switch back to anoperating mode from sleep mode quickly without pressing buttons ortouching the display screen.

SUMMARY

The summary of the invention is not to be used as a basis to interpret ascope of the appended claims, as the claimed invention is far broaderthan the description in this summary.

An apparatus and method for waking up a main processor in an ultra-lowpower device preferably includes a main processor, and a sub-processorthat utilizes less power than the main processor, and may beinternalized in the main processor. According to an exemplary aspect ofthe presently claimed invention, at least one sensor is preferably aninterrupt-type sensor (as opposed to, for example, a polling-typesensor). One of the many advantages of the presently claimed inventionis that both the main processor and the sub-processor can remain insleep mode, as a low-power or an ultra-low power sensor can operate withthe sub- processor being in sleep mode and only awaken after receivingan interrupt signal from the interrupt sensor that a change has beendetected.

In addition, the presently claimed invention also permits a return fromsleep mode to operating mode by a mere wave of the hand, which isunknown heretofore. Also, shaking the unit, or moving a stylus penarranged along an exterior of the device are all examples of the manyways the device can be awakened from sleep mode.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other exemplary aspects of the invention will become moreapparent from the following detailed description taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 shows a block diagram of an exemplary depiction of an apparatusaccording to an exemplary aspect of the invention;

FIG. 2 shows a flowchart illustrating an exemplary operation for gesturesensing according to an exemplary aspect of the invention;

FIG. 3A shows a flowchart illustrating an exemplary operation of afeedback voice input based on device's motion according to an exemplaryaspect of the invention;

FIG. 3B is an exemplary overview of an AP Processor to Hub ProcessorProtocol according to an illustrative aspect of the present invention;

FIG. 3C is an example of a message frame that can be used with an AP toHub Protocol according to an illustrative aspect of the presentinvention;

FIG. 3D is an example of an AP processor communicating with a secondprocessor hub, according to an AP to Hub protocol that can be used withthe present invention;

FIG. 4 shows a flowchart illustrating exemplary operation of a signatureunlock based on stylus movement according to an exemplary aspect of theinvention;

FIG. 5 shows a current profiling example according to an exemplaryaspect of the invention; and

FIG. 6 shows an example of a wireless device incorporating the presentinvention.

It is to be understood, however, that the drawings are designed solelyfor purposes of illustration and not as a definition of the limits ofthe invention, for which reference should be made to the appendedclaims. Moreover, the drawings are not necessarily drawn to scale and,unless otherwise indicated, they are merely intended to conceptuallyillustrate the structures and at least one of a low power processor andan ultra-low power sensor to monitor at least one of the signals,commands, inputs, and changes in the environment. The circuit wakes upthe main processor responsive to one of the low power processor and theultra-low power interrupt sensor.

DETAILED DESCRIPTION

The present invention has been described with respect to particularexemplary embodiments and with reference to certain drawings, but theinvention is not limited thereto, but rather, is set forth only by theappended claims. The drawings described are only schematic and arenon-limiting. In the drawings, for illustrative purposes, the size ofsome of the elements may be exaggerated and not drawn to a particularscale. Where the term “comprising” is used in the present descriptionand claims, it does not exclude other elements or steps. Where anindefinite or definite article is used when referring to a singularnoun, e.g. “a” “an” or “the”, this includes a plural of that noun unlesssomething otherwise is specifically stated. Hence, the term “comprising”should not be interpreted as being restricted to the items listedthereafter; it does not exclude other elements or steps, and so thescope of the expression “a device comprising items A and B” should notbe limited to devices consisting only of components A and B. Thisexpression signifies that, with respect to the present invention, theonly relevant components of the device are A and B.

Furthermore, the terms “first”, “second”, “third” and the like, if usedin the description and in the claims, are provided for distinguishingbetween similar elements and not necessarily for describing a sequentialor chronological order. It is to be understood that the terms so usedare interchangeable under appropriate circumstances (unless clearlydisclosed otherwise) and that the exemplary embodiments of the inventiondescribed herein and may be operated in other sequences and/orarrangements than are described or illustrated herein.

Definitions:

To aide in an understanding of the present invention, an artisan shouldunderstand and appreciate that the terms “main processor” andsub-processor” are terminologies used for understanding of theinvention, but other terminologies can be interchangeably used in placeof main processor and sub-processor having the same meaning.

For example, to aid the artisan, the term “main processor”, can be anyone of an “application processor”, “AP” , “first processor”, and“processor 1” as used herein all refer to the same processor 110 that isshown in FIG. 1. A high power processor can be referred to as a mainprocessor, or an application processor. The main processor typically isconsidered high power relative to the low power sub-processor or sensingprocessor.

In addition, the term “sub-processor”, can be any one of a “sensingprocessor”, “MCU”, “second processor”, “processor 2”, “Sensor Hub(Processor)”, MCU (Micro Controller Unit”, I refer to the same processor120 that is shown in FIG. 1. An ultra-low power processor can bereferred to as any of the above.

An artisan understands and appreciates that the term “ultra-low power”typically refers to a processor operating at power consumption valuesusing less than approximately 1 mA, and often in the μA range.“Ultra-low power levels” refers to power consumption at levels usingless than approximately 1 mA.

In addition, the artisan also understands and appreciates that the term“low power” typically refers to a processor (or sub-processor) operatingin the 1-10 mA range. The apparatus may comprise a wirelesscommunication device, such as a mobile communication terminal, acellphone, smart phone, tablet, Personal Digital Assistant (PDA),notebook, netbook, etc. just to name a few possible non-limitingexamples of devices.

FIG. 1 shows a block diagram of an exemplary depiction of an apparatus100 according to an exemplary aspect of the invention that includes amain processor (HP for high power) that is typically an applicationprocessor, a sub-processor 120 (LP for low power) that receivesinformation from sensors such as interrupt uLP sensor 130 (ultra-lowpower) and a polling 140 (that may or may not be ultra-low power).

The sub-processor 120 operates at a low power or ultra-low power, andaccording to the present invention, the sub-processor can remain in asleep mode along with the main processor 110 because of the use of aninterrupt sensor 130. As discussed herein above, the conventionalapparatus uses only a polling sensor that requires either the mainprocessor or the sub-processing to remain fully operational to be ableto have the device change from sleep mode to operational mode.

The interrupt sensor 130 operates at ultra-low power levels and sends aninterrupt signal to the sub-processor 120 when a predetermined conditionis sensed, which can be, for example, waiving one's hand in front of thedisplay, shaking the device, or moving a piece of the device, such asshifting a position of a stylus 475 (FIG. 4) or part of the cover.According to the present invention, the interrupt sensor 130 is operablewhile the sub-processor 120 is in sleep mode. However, the pollingsensor 140 requires the sub-processor to be in awake mode or operatingmode (not in sleep mode).

FIG. 2 shows a flowchart illustrating an exemplary operation for gesturesensing according to an exemplary aspect of the invention.

At step 200, the main processor 110 and sub-processor 120 are in sleepmode. At steps 210 and 220, an interrupt sensor 130 (including but notlimited to an infrared (IR) sensor) detects gesture sensoring within aproximity distance of the electronic device, typically a display ortouchscreen. The proximity distance can be, for example, 10-15 cm, butthe invention does not require a specific distance, so long as thesensor can recognize the wave of the user's hand.

At step 230, the sub-processor 120 is awakened by the interrupt signalsent from the interrupt sensor 130. Alternatively, at step 240 anaccelerometer may detect the device being shaken or waived, and alsocause the sub-processor 120 to be awakened.

At step 250, the sub-processor determines whether or not the sensed datafrom the interrupt sensor 130 is valid by comparing the value with atable in storage.

In addition, a polling sensor 130 can be optionally included so thatwhen the mobile device is placed in a case or bag, the interrupt sensordoes not unintentionally operate. Accordingly, the sub-processor wakesup due to the interrupt from the interrupt sensor, and the mainprocessor wakes up when 1) sensing data of the interrupt sensor iswithin valid range or 2) when sensing data of the polling sensor iswithin the valid range, with 1) or 2) being determined by thesub-processor at step 250.

After determining by the sub-processor 120 that the data is valid, forexample, by being in a valid range, or has reached a predeterminedthreshold, the sub-processor 120 at step 260 then wakes the mainprocessor 110, which in turn at step 270 provides feedback to the user,in the form of, for example, unlocking the screen, prompting the user,making the display operable, showing a home screen, etc. According to anexemplary aspect of the present invention, the predetermined thresholdcould be a particular value which if the output is greater than or equalto, is determined by the sub-processor as satisfying the wake upcondition(s). In addition, there can be a range of range of valuesreceived from the sensor that are predetermined as satisfying a wakeupcondition, that being provided only for purposes of illustration and notfor limiting the appended claims, such as, for example a microvolt uv(or microamp ua) range. Any other such range (e.g. ma) that is withinthe capability of the sub-processor to distinguish between valuesreceived from the sensor so as ascertain a valid range or predeterminedthreshold are within the spirit and scope of the claimed invention.

FIG. 3A shows a flowchart illustrating an exemplary operation of afeedback voice input based on device's motion according to an exemplaryaspect of the invention. This particular exemplary embodiment starts atstep 300 with the main processor and sub-processor being asleep. Amotion detector detects motion at step 310, by sensing the predeterminedcondition (in this example is the device being shaken or waved) at step320, and the interrupt signal is sent to the sub-processor 120 to wakeup the sensing processor at step 330. Then the sub-processor at step 340determines whether or not the sensed data is valid, by comparing withvalues in storage to determine if the data is within a valid range orhas reached a predetermined threshold, for example. Upon determiningthat the sensed data from the interrupt sensor is valid, then at step350 the sub-processor 120 wakes up the main processor 110. The mainprocessor can be fully operable and wait, for example, for a voice input(step 360), and based on the determined voice input, can either unlockthe display screen or execute a function or application (step 370). Forfurther purposes of illustration and not to limit the claimed invention,exemplary protocol between the main processor and sub-processor isdiscussed herein. The protocol for transmitting is in accordance withthe main processor and sub-processor's active or sleep state.

As shown in FIG. 3B, while the main processor is active, an exchangeoccurs between main processor and a sub-processor according to a HUBprotocol. First, a hub interrupt is sent by the main processor to thesub-processor, and wherein the main processor starts to send lengthinformation. In turn, the sub-processor sends an acknowledgement back tothe main processor. At this point, the hub (sub-processor) sets thecontrol right and AP sleep information.

With continued reference to FIG. 3B, it can be seen that thesub-processor keeps varying states between active and sleep. When asituation arise where the main processor needs to be awakened, an APinterrupt id from the sub-processor to the main processor. Once the mainprocessor is awakened, the main processor remains in an active state andstarts to send information to the sub-processor. In turn, thesub-processor indicates to the main processor the data length to send.Next the main processor starts to read a message from sub-processor,which can comprise sensor data and sub-processed data.

FIG. 3C shows an example of a main processor to sub-processor (i.e. APto Hub Protocol Message Frame) that can be used according to anexemplary aspect of the present invention.

Referring now to FIG. 3C, it is shown that an exemplary frame can be 8bytes, with a command field commanded by the AP (main processor) to theHub (sub-processor), a sensor number field specifying a particularsensor, s data type showing the content of the operand beingtransmitted, a data size field providing the actual data that follows.Each of the aforementioned parts of the message frame can be 1 byte inlength, and the data and status can be 4 bytes each so as to total 8bytes, for example.

FIG. 3D shows another example of AP (main processor) to Hub(Sub-processor Protocol according to a non-limiting exemplary aspect ofthe present invention. These actions are similar to what is shown inFIG. 3B while the AP is in the active mode.

FIG. 4 shows a flowchart illustrating exemplary operation of a signatureunlock based on stylus movement according to an exemplary aspect of theinvention.

With reference to FIG. 4, at step 400, the main processor andsub-processor are in sleep mode. At step 410, the presence of a styluspen 475 is monitored to determine whether the stylus pen has beenremoved from a holder on the electronic device. At step 420, when it isdetermined that the stylus pen is removed, sub-processor wakes up at430. If at step 440, the non-input timer has expired, the main processorand sub-processor go back to sleep mode, otherwise, at step 450 it isdetermined whether a signature is valid, and if so, then main processorwakes up, and the display LCD is turned on and unlocked (step 460).

FIG. 5 shows a current profiling example according to an exemplaryaspect of the invention. In this particular non-limiting example, The Xaxis is time, and the Y-axis is current consumption which comprisesmilliamps and microamps.

As shown in FIG. 5, the IR gesture sensor (interrupt sensor) consumes at317.5 uA of current. The sub-processor in this example consumes about3.2 uA when awakened due to the IR gesture sensor sensing a change inthe ambient condition. Within about 330 ms of waking up thesub-processor may wake up the main processor to perform a function, andupon doing so, the sub-processor goes back to sleep. The main processorconsumes considerably more current than the sub-processor. Also, in theexample of FIG. 5, it is shown that the accelerometer can cause the mainprocessor to wake up within 180 ms.

FIG. 6 shows one possible example of a wireless device incorporating thepresent invention. An artisan understands and appreciates that aplurality of both wired and wireless devices can benefit from theclaimed invention. Some non-limiting examples include smartphone,tablet, PDA, music player, etc. just to name a few examples. Acontroller includes the main processor 610 and a codec 617, thecontroller communicates with sensing processor 620. The interrupt sensor630 and the polling sensor 640 are shown schematically, but their actualproximity to the controller us likely to be different than shown.

Touch screen 655 permits display and entry of data. Storage device 685is in communication with the controller, and comprises a non-transitorymachine readable medium.

Auxiliary input 675 can be anything from a keyboard to a mouse, andwireless communication device, shown as a single box, may be differenthardware modules for transmitting in short range communication such asNear Field Communication, Bluetooth, WLAN, 802.11, RF communications,etc.

In the invention, the ambient environment is monitored by an interruptsensor, so that the sub-processor and the main processor (applicationprocessor) can remain together in sleep mode. Not only does theinvention save power, but provides the user with a convenience in thatthere is no requirement to push a button to activate/convert the devicefrom a sleep mode back to a normal operating mode.

The sensing of a swiping near the device is sufficient to awake thedevice from sleep mode, or alternatively, shaking or waving the device,also restores the device to a normal operating state by waking it up.

The above-described methods according to the present invention can beimplemented in hardware, firmware or as software or computer code thatcan be stored in a recording medium such as a CD ROM, an RAM, a floppydisk, a hard disk, or a magneto-optical disk or computer code downloadedover a network originally stored on a remote recording medium or anon-transitory machine readable medium and to be stored on a localrecording medium, so that the methods described herein can be renderedin such software that is stored on the recording medium using a generalpurpose computer, or a special processor or in programmable or dedicatedhardware, such as, flash, an ASIC or FPGA. As would be understood in theart, the computer, the processor, microprocessor controller or theprogrammable hardware include memory components, e.g., RAM, ROM, Flash,etc. that may store or receive software or computer code that whenaccessed and executed by the computer, processor or hardware implementthe processing methods described herein. In addition, it would berecognized that when a general purpose computer accesses code forimplementing the processing shown herein, the execution of the codetransforms the general purpose computer into a special purpose computerfor executing the processing shown herein.

What is claimed is:
 1. A method comprising: receiving an input via atouch screen of an electronic device including a first processor and asecond processor, the touch screen being operatively coupled with thefirst processor while the second processor is in an inactive state;determining whether the input matches data stored by the secondprocessor; and sending a signal from the first processor to the secondprocessor to transition the second processor from the inactive state toan active state, the sending based at least in part on a determinationthat the input matches the data.
 2. The method of claim 1, wherein thereceiving comprises: transitioning the first processor from an activestate to an inactive state if no input has been obtained at the firstprocessor for a specified time period.
 3. The method of claim 1, whereinthe first processor is operated using a first power level, and thesecond processor is operated using a second power level higher than thefirst power level.
 4. The method of claim 1, wherein the transitioningcomprises: performing a specified function in response to the inputusing the second processor transitioned to the active state.
 5. Themethod of claim 4, wherein the specified function comprises: a functionto unlock a locked function of the electronic device.
 6. The method ofclaim 1, further comprising: detecting a change in an ambientenvironment of the electronic device using one or more sensorsoperatively coupled with the first processor; and transitioning thefirst processor from an inactive state to an active state based at leastin part on the detecting of the change.
 7. The method of claim 6,wherein the one or more sensors include a first sensor to detect anobject external to the electronic device or a second sensor to detect amotion of the electronic device.
 8. The method of claim 6, wherein theone or more sensors comprise the touch screen.
 9. The method of claim 1,further comprising: transitioning the first processor from an activestate to an inactive state based at least in part on a determinationthat the input does not match the data; and detecting a change in anambient environment of the electronic device using one or more sensorsoperatively coupled with the first processor.
 10. An apparatuscomprising: a memory to store data corresponding to user authorization;one or more sensors to detect a change in an ambient environment of theapparatus; and one or more processors configured to: receive an inputcorresponding to the change using at least one sensor of the one or moresensors while a display operatively coupled with the one or moreprocessors is in an inactive state; determine whether the input matchesthe data; and transition the display from the inactive state to anactive state based at least in part on a determination that the inputmatches the data.
 11. The apparatus of claim 10, wherein the one or moreprocessors are configured to: transition the one or more processors froman active state to the inactive state if no input has been received fora specified time period.
 12. The apparatus of claim 10, wherein the oneor more processors are configured to: perform a specified function inresponse to the input.
 13. The apparatus of claim 10, wherein the one ormore processors are configured to turn on the display as at least partof the transitioning.
 14. The apparatus of claim 10, wherein the one ormore sensors comprise a first sensor to detect an object external to theapparatus or a second sensor to detect a motion of the apparatus. 15.The apparatus of claim 10, wherein the at least one sensor comprises atouch screen.
 16. The apparatus of claim 10, wherein the one or moreprocessors are configured to refrain from activating the display basedat least in part on a determination that the input does not match thedata.
 17. An apparatus comprising: one or more sensors to detect achange in an ambient environment of the apparatus; a first processor tocontrol at least one sensor of the one or more sensors; and a secondprocessor to execute an application, wherein the first processor isconfigured to: receive an input corresponding to the change from the atleast one sensor; determine whether the input meets a specifiedcondition; and based at least in part on a determination that the inputmeets the specified condition, send to the second processor a request totransition the second processor from an inactive state to an activestate.
 18. The apparatus of claim 17, wherein the one or more sensorscomprise an infrared sensor to detect an object external to theapparatus.
 19. The apparatus of claim 17, wherein the first processor isconfigured to: detect an existence of an external object or movement ofthe apparatus, as at least part of the specified condition.
 20. Theapparatus of claim 17, wherein the first processor are configured to:transition to an active state in response to the input while the secondprocessor is in the inactive state.